Called my work cell phone  and left no message. found this on another website:
"IRS SCAMMERS on 503-606-8332! Claiming they are filing a lawsuit against me and demanding money. Do not call them back! They are SCAMMERS! IRS will never call you, they'll mail you! "

Scam IRS call.
Call them back and say your an IRS Field agent.
See them run like the rats they are!!